Community Water System · PWS CA3310025
Norco, City Of
Operator location Norco, California - 24% of 144 violations are health-based (upper-third health share (> 23%)); surface water source; 25,068 served per SDWIS.
- 25,068
- People served (this PWS)
- 144
- EPA violations (this PWS)
- 35
- Health-based (this PWS)
- 7 PFAS
- UCMR5 (this PWS)
Norco, City Of standing, high SDWIS violation third
24% of 144 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 24% is upper-third health share (> 23%). UCMR5: upper-third PFAS panel (> 4 compounds). Population rank #2,212 of 29,740 among systems serving 500+.
The verdict
Norco, City Of sits in the upper third of the sitemap cohort by violation count (144), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (25,068; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 24% - most of this ledger is MCL or treatment-technique exceedance. UCMR5 detected 7 PFAS compounds (upper-third PFAS panel (> 4 compounds)).
- #2,212 of 29,740
- Population · /systems
- #310 of 1,701
- Population · CA
- 144
- Total EPA violations on record
- 24%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
7 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 7,100
- County
- Riverside
- School/Daycare
- No
- MCL Violations
- 35
- Monitoring Violations
- 101
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Nitrate | MCL | 22 | 2011 |
| Coliform (TCR) | MCL | 8 | 2013 |
| Nitrate | MR | 5 | 2009 |
| Coliform (TCR) | MR | 4 | 2009 |
| Arsenic | MCL | 4 | 2007 |
| Benzene | MR | 4 | 2012 |
| Arsenic | MR | 4 | 2024 |
| Consumer Confidence Rule | Other | 2 | 2001 |
| Barium | MR | 2 | 2024 |
| Cadmium | MR | 2 | 2024 |
| Chromium | MR | 2 | 2024 |
| Fluoride | MR | 2 | 2024 |
| Mercury | MR | 2 | 2024 |
| Nickel | MR | 2 | 2024 |
| Nitrite | MR | 2 | 2024 |
| Antimony, Total | MR | 2 | 2024 |
| Beryllium, Total | MR | 2 | 2024 |
| Thallium, Total | MR | 2 | 2024 |
| Selenium | MR | 2 | 2024 |
| Methoxychlor | MR | 2 | 2024 |
| Dalapon | MR | 2 | 2024 |
| Endothall | MR | 2 | 2024 |
| Glyphosate | MR | 2 | 2024 |
| Di(2-ethylhexyl) adipate | MR | 2 | 2024 |
| OXAMYL | MR | 2 | 2024 |
| Simazine | MR | 2 | 2024 |
| Dinoseb | MR | 2 | 2024 |
| Hexachlorocyclopentadiene | MR | 2 | 2024 |
| LASSO | MR | 2 | 2024 |
| 2,3,7,8-TCDD | MR | 2 | 2024 |
Violation Count vs. the National Corpus
Norco, City Of has 144 recorded EPA violations, 80% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 20% carry more. 24% of this system's own violations are health-based (35 of 144), and it ranks #2,212 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
144 Higher than most more violations than 80% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 30 of 406 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFDoA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| ADONA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFUnA | 9/12/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFHxA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 9/12/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBA | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFNA | 9/12/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| HFPO-DA | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHxS | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOS | 9/12/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFTA | 9/12/2023 | <8.00 ppt | 8.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/12/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| 6:2 FTS | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| NMeFOSAA | 9/12/2023 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFTrDA | 9/12/2023 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFHpS | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 9/12/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| NEtFOSAA | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 9/12/2023 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFMPA | 9/12/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 9/12/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| HFPO-DA | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/12/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFBA | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| ADONA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 9/12/2023 | 5.90 ppt | 3.00 ppt | Detected |
| PFMBA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 9/12/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| NFDHA | 9/12/2023 | <20.00 ppt | 20.00 ppt | Not Detected |
| NEtFOSAA | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 8:2 FTS | 9/12/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 9/12/2023 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFUnA | 9/12/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFTrDA | 9/12/2023 | <7.00 ppt | 7.00 ppt | Not Detected |
| NMeFOSAA | 9/12/2023 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFBS | 9/12/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
Health-based violations on Norco, City Of
35 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for CA3310025.
Sources: EPA SDWIS · California State Water Resources Control Board, Division of Drinking Water
Nationwide peers
144 violations · 25,068 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems with similar served population
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Norco, City Of
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in California compares on the same EPA violation measures. California systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.